Vehicle brake



June 1, 1937. G H, T NER 2,082,229

VEHICLE BRAKE Filed Feb. 7, 1935 2 Sheets-Sheet l June 1, 1937. STONER2,082,229

VEHICLE BRAKE Filed Feb 7, 1935 2 Sheets-Sheet? 2/ 20 T Z? 1% 36 lg.% 647 6 6 INVEN+ m Patented June 1,1937

UNITED STATES PATENT OFFICE VEHICLE BRAKE Application February 7, 1935,Serial No. 5,410

5 Claims.

This invention relates to vehicle brakes of the internal expanding typeand more specifically to brakes of this type in which the brake shoesare mounted upon an anchor which is movably carried by the backingplate.

It is an object of the invention to provide a I simple arrangementwhereby the. brake shoes may be adjusted to provide the desiredclearance between the same and the rotatable drum to compensate for wearof the brake lining. The invention is especially adapted for use in thetype of vehicle brake in which the brake shoes are mounted upon ananchor which is movably carried by the backing plate.

Before explaining in detailthe present invention it is to be understoodthat the invention is not limited in its application to the details ofconstruction and arrangement of parts illustrated in the accompanyingdrawings, since the invention is capable of other embodiments and ofbeing practiced or carried out in various ways. Also it is to beunderstood that the phraseology or terminology employed herein is forthe purpose of description and not of limitation, and it is not intendedto limit the invention claimed herein beyond the requirements of theprior art.

The invention will be more clearly understood from the followingdescription in conjunction with the accompanying drawings, in which:

Fig. 1 is a sectional elevational view of a vehicle brake embodying theinvention.

Fig. 2 is a plan view partly in section and partly broken away, the drumbeing omitted.

Fig. 3 is a section taken on line 3-3 of Fig. 1.

Fig. 4 is a sectional view taken on the line 4-4 of Fig. 1.

Fig. 5 is a sectional View taken upon the line 5-5 of Fig. 1.

Fig. 6 is an enlarged detail perspective view of a portion of the brakeshowing the parts separated.

Fig. 7 is a sectional View taken upon the line 1-1 of Fig. 1.

Fig. 8 is a fragmentary view similar to that of Fig. 1 but showing theparts in a different position.

One embodiment of the invention is illustrated in Figs. 1 to 8 inclusiveof the accompanying drawings and comprises a backing plate Ill adaptedto be fixed to a stationary part of the vehicle and a rotatable drum lladapted to be mounted upon a vehicle wheel. A pair of brake shoes I2 andI3, each having a suitable brake lining l4 fixed upon its outer surface,are pivotally carried by an anchor assembly A which is movably carriedby the backing plate I0. I

The anchor assembly A comprises an arm one end of which is pivotallymounted upon a stud it fixed in the backing plate I0. The arm 5 I5 isprovided near its other end with a bearing surface IT adapted torotatably receive the intermediate portion i8 of a shaft 19. One end ofthe shaft 19 projects through a hole I of greater diameter in thebacking plate and is provided with 10 a threaded portion 20 adapted toreceive a nut 2 l Between the portions l8 and 20, the shaft I9 isprovided with a portion 22 of square cross section adapted to engage thesquare hole 23 of a looking plate 24 having an arcuate slot 25. Thelock- 15 mg plate 24 is secured to the arm l5 by a screw 2% passingthrough the slot 25 in said plate and the hole 'I' in the backing plateand engaging a threaded hole 21 in the arm 15 to. lock the shaft it uponthe arm l5 and prevent relative movement therebetween. The screw 26 alsopasses through a washer 8 which is interposed between the plate 2 1 andthe arm E5.

The other end of the shaft I9 is provided with a cam 30 adapted toengage the inner surfaces 25 3| and 32 of a split bearing B havingportions 33 and 34. The portions 33 and 34 of the split bearing B areeach provided with a tongue 35 adapted to slidably engage a groove 36formed in one face of the arm IS. The adjacent ends 30 of the brakeshoes !2 and I3 are formed with bearing surfaces 38 and 39 respectivelyof cylindrical shape adapted to engage the cylindricallyshaped bearingsurfaces 40 and 4| (see Fig. 6) formed upon the outer surface of theportions 35 33 and 3 5 respectively of the split bearing B. The adjacentends of the brake shoes l2 and I3 are held between shoulders 33, formedupon the portions 33 and 3 3 of the split bearing, and a cap plate 44secured upon the outerend of the 40 cam 30 by a screw 45.

Preferably, the brake shoes I 2 and I3 are moved outwardly intoengagement with the drum II by a floating cam C which may be of anysuitable construction. As illustrated, the cam C comprises 5 acylindrical block 58 having diametrically opposite grooves 51 formed inits periphery. The bottom surfaces of the grooves 5| are shaped toprovide cam surfaces 52. One face of the block is provided with aT-shaped slot 53 adapted to 50 receive the rectangular-shaped head 54formed upon the end of a shaft 55 which is mounted for rotation in abearing 58 fixed in the backing plate It]. A crank 51 is fixed upon theother end of the shaft 55 and is operatively connected in any suit- 55able manner with the vehicle brake operating mechanism. The unsupportedends of the brake shoes I2 and I 3 are received in the grooves 5| so asto be engaged by the cam surfaces 52. If desired the brake shoes I2 and13 may be centered and guided in their movement by centering and guidingdevices carried by the backing plate In and having a T-shaped head 6|adapted to be received in a pocket formed between the web of the brakeshoe and an off-set plate 62 suitably secured thereto. j

The brake shoes 12 and I3 are normally held in their retracted positionout of engagement with the brake drum l l by springs 63 extendingtherebetween and also by a spring 64 one end of which is connected to astud. 65 fixed upon the backing plate l0 and the other end of which isconnected to a stud 66 fixed in the free end of the-arm 1'5. When thebrake linings l4 have become worn so that it is desirable to adjust thebrake shoes l2 and I3 to provide the desired olearancebetween the brakelinings l4 and the drum H, the screw 26 is loosened to unlock the plate24 so as to permit the latter and the shaft [9 to be rotated. As theshaft I9 is rotated the portions 33 and 34 of the split bearing B aremoved outwardly in substantially opposite directions so as to bring thebrake shoes l2 and 13 closer to the inner surface of the drum H toprovide the desired clearance therebetween when the brake shoes are intheir released or retracted position. The screw 26 is then tightened tolock the plate 24 and the shaft l9 upon the arm I5.

I claim:

1. In a vehicle brake, in combination, a rotatable brake drum, a backingplate, a pair of brake shoes, and means carried by said backing plateand movable relative thereto for supporting said shoes, said meansincluding a member adapted to be adjustably positioned thereon to changethe position of said shoes relative to said drum, bearings interposedbetween said member and said shoes, and means for slidably guiding saidbearmgs.

one end pivotally mounted on the backing plate,

a pair of brake shoes, and means carried by said arm for supporting saidshoes, said means comprising a member movably mounted on said arm .toadjust the position of said shoes relative to said drum, and means forlocking said member on said arm.

4. In a vehicle brake, in combination, a rotatable brake drum, a backingplate, an arm having one end pivotally mounted on the backing plate, apair of brake shoes, and means carried by saidarm for supporting saidshoes, said means comprising bearings adapted to be rotatably engaged byadjacent ends of said shoes, a member movably mounted on said armadapted to engage said bearings to move the same toward said drum whensaid member is moved relative to said arm, means for slidably guidingsaid bearings toward said drum, and means for locking said member onsaid arm.

5. In a vehicle brake, in combination, a rotatable brake drum, a backingplate, an arm having one end pivotally mounted on the backing plate, apair of brake shoes, and means carried by said arm for supporting saidshoes, said means comprising bearings adapted to be rotatably engaged byadjacent ends of said shoes, a shaft rotatably mounted in said arm, acam carried by said shaft adapted to engage said bearings to move thesame toward said drum, means for 'slidably guiding said bearings towardsaid drum, and means for locking said shaft on said arm.

GEORGE H. STONER.

